Coloring rubber



Patented Mar. 28, 1939 UNITED STATES PATENT OFFICE COLORING RUBBER Walter Fairbairn Smith, Blackley, Manchester,

England, assignor to Imperial Chemical Industries Limited, a corporation of Great Britain No Drawing. Application March 4, 1936, Serial No. 67,175. In Great Britain March 4, 1935 8 Claims. (CI. 18-50) According to this invention I color rubber su- A portion of the thin vulcanised sheet was then perficially by incorporating an arylamide, as deimmersed in a warm aqueous solution of diazofined below, into rubber in bulk, vulcanise if vultised p-nitroaniline, when after a few minutes canised rubber is required, and then treat with immersion the surface of the rubber becomes an aqueous solution of a diazotised amine so that red. A cutting through the sheet shows that the 3 coupling takes place. color has penetrated slightly into the mass. With Incorporation may be effected by milling when a sheet about one sixteenth of an inch in thickusing rubber, or by adding to the latex when nessa deep reddish violet shade is obtained. This using rubber latex. shade is almost the same as that given by the As arylamides I use those which may be used ame Co pone ts 011 c tto 10 in coloring cotton by impregnating with the aryl- The colors obtained by using other arylamides amide and coupling on the cotton with a diazoand amines in the process of this example are tised arylamine; especially suitable are arylashown in the following table.

mides of 2 3-hydroxynaphthoic acid and acetoaceticarylamides. As arylamines I use those (includ- Arylamide Amino Color 16 ing aminoazo compounds) which may be used in coupling with the arylamides on the cotton fibre.

2-hydroxynaphthalenc- 6 -benzoylamino -4- meth Red-violet.

The invention is primarily suitable for color- B-carboxylicanilide. ogcy-m-toluidine. ing rubber in the form of thin sheet or filament. gi ggigggflgfiiggggj ammwfimsldme Blue'red 20 The process of the invention works equally well thgamide. Ch] T 0 d 20 with thick materials and can be used for these o8:::::::::::::::::: {Jibh1oit fi tifi aiiirajj oifillti'ri Where the cost of the extra arylamide needed is Bisaeetoacetic-o-tolidide. m-Chloroaniline Yellow. no objection.

4-chloro-o-toluidine Reddish-yellow.

By working according to my process the rubber is colored in shades which are fast to light and which are also fast to rubbing if a washing with hot soap and water is given after dyeing.

Example 2.--The following rubber mix was prepared in the usual manner.

Also, deep shades can be obtained with small pro- Crepe rubber 63 portions of arylamides calculated on the weight White Substitute 30 of the rubber mix or latex. Lithopone 40 30 In treating the rubber with diazotised amine, Whiting 164 a textile material which has been impregnated Paramn Wax 4 with an arylamide in the usual way may be Bjsacetoacetic o toudide 29 treated at the same time. In this way an article or material made up of rubber and a textile may Thin Sheets of thls mm were Vulcamsed by a have the rubber and the textile both colored mersing for about sfwmds in a 5% 9 of with the Same azoic coloring matten sulphur monochlonde in benzene stored 1n awarm The following examples in which parts are by fi m for 1 u and then F P by weight illustrate but do not limit the invention. Freatmg Wlth ammoma- The Sheet lmmersed 4U EmmpZe foll win rubber mix was in a warm aqueous solution of diazotised 4-ben- 40 pared in the usual manner zoyl-2:5-d1ethoxyamhne. After a few minutes the surface becomes yellow. Parts With the same arylamide, diazotised 4-amino- R 100 4-methoxydiphenylamine gives a light brown Zmcox1de 5 Lithopone 2 I claim: Blane t 1. An article of cured compounded rubber acld 1 comprising a water-insoluble azo dye coupling ur 7 component milled throughout the body of the 50 ggggg? (reglstered tlade'mark) I 05 rubber, said coupling component being one of 50 ahydmxynigtaiasiztzrtanzaaaa the w resisting of a 2ii341mm-neohflmi (arylamide) 0.8 i. e. of the mix ylamide n which aryl is of the benzene and naphthalene series and an aceto-acetic arylamide The mix was then sheeted thinly and cured in of the benzene series, and a surface layer comthe press for 13 minutes at 141 C. prising an azo dye formed by coupling said com- 55 ponent with a diazotized arylamine, said surface layer being coextensive in thickness with the penetration of said diazotized arylamine into the rubber when the cured rubber is immersed in an aqueous solution of said amine.

2. The process for the superficial coloration of rubber which comprises milling throughout the unvulcanized rubber an insoluble azo dye coupling component of the group consisting of the 2:3-hydroxynaphthoic arylamides in which aryl is of the benzene and naphthalene series and an aceto-acetic arylamide of the benzene series, vulcanizing the rubber, and thereafter treating the rubber with an aqueous solution of a diazotized arylamine until a surface layer of the rubber is dyed.

3. Process for superficial coloration of rubber, which comprises milling the rubber with an arylamide coupling component of the type used in dyeing cotton by the ice-color method, vulcanizing and forming the rubber, and thereafter treating the rubber with an aqueous solution of a diazotized arylamine.

4. Process as claimed in claim 3 in which the arylamide coupling component is a 2:3-hydroxynaphthoic arylamide.

5. Process as claimed in claim 3 in which the arylamide coupling component is an acylacetic arylamide.

6. Process as claimed in claim 3 in which the arylamide coupling component is 2:3-hydroxynaphthoic anilide.

'7. Process as claimed in claim 3 in which the arylamide coupling component is 2:3-hydroxynaphthoic-u naphthylamide.

8. Process as claimed in claim 3 in which the arylamide coupling component is bisacetoacetic tolidide.

WALTER FAIRBAIRN SMITH. 

